Dispensing machine for filling containers



Jan. 7, 1964 P. LOHSE ETAL 3,116,765

DISPENSING MACHINE FOR FILLING CONTAINERS Filed March 15, 1961 s Sheets-Sheet 1 Jan. 7, 1964 DISPENSING MACHINE FOR Filed March 15, 1961 P. LOHSE ETAL FILLING CONTAINERS 3 Sheets-Sheet 2 Jan. 7, 1964 P. LOHSE- ETAL DISPENSING MACHINE FOR FILLING CONTAINERS 3 Sheets-Sheet 3 Filed March 15, 1961 u lm ww! United States Patent 3,116,766 DISPENSING MACHINE FUR FILLING CONTAINERS Paul Lohse, Stuttgart-Bad Cannstatt, and Theodor Jungmayr, Stuttgart-Nerd, Germany, assignors to Firrna Fr. Hesser Maschinenfabrik-Ahtiengesellschaft, Stuttgart-Bad Cannstatt, Germany, a corporation of Germany Filed Mar. 15, 1961, Ser. No. 95,985 Claims priority, application Germany Mar. 18, 1960 12 Claims. ((11. 141-161) This invention relates to an improved construction for drive means for dispensing screws in machines for the dispensing of measured quantities of material.

One conventional term of machine of this character, for example, has a rotary drum which carries at least one chute or hopper at its underside terminating in a discharge nozzle housing a dispensing screw. Material to be dispensed is fed into the drum and passes into the hopper or hoppers for measured dispensing, by controlled rotation of the respective screw. The measured material is dispensed into containers or packages moved to a position beneath the discharge nozzle by a conveyor.

In known screw dispensing machines the screw is driven from a continuously roating motor through a controlling clutch, for example a friction clutch, which is operated tor timed periods or in accordance with a pre established number of rotations of the screw. Experience has indicated that, in the case of a timed operation, the slip which occurs in the clutch between the driving and driven parts of the latter provides a number of screw rotations per dispensing operation which is not constant and consequently the discharge material exhibits larger or smaller differences in weight. Attempts have therefore been made to operate the clutch of the dispensing screw in response to the desired number of rotations of the latter through a counter mechanism adjoining the screw shaft' This construction, however, is complex and is therefore comparatively expensive.

It is an object of the invention to remedy the above shortcomings and to provide a clutch operated screw which is simple and easy to manutfacture.

It is a further object of the invention to provide a friction clutch in which there is substantially no difference between the rates of rotation of the driven and the driving elements, at the time of engagement, so that there is no appreciable slip at any time in the clutch transmission.

It is a still further object of the invention to make available clutches having interlocking elements which, hitherto, it has not been possible to employ very often because of the fact that they make a hard engagement. Yet a further object of the invention is to allow simple timed controls to be used both for impositivelyas well as positively-acting clutches without incurring the failures referred to above.

Yet another object is to associate with the clutch which transmits the drive to the dispensing screw a synchronizing means which equalizes the rotary movement of the driven and driving clutch elements before the clutch elements are engaged.

Particular details and advantages of the invention are disclosed in the following description of particular enibodirnents thereof which are illustrated in the accompanying drawings:

FIGURES 1a and lb are partial cross section through a screw dispensing machine having rotary dispensing devices shown in two parts joined along lines I-I.

FIGURE 2 is a plan view of the screw dispensing machine of FIGURE 1, with a part thereof shown in section.

FIGURES 3 and 4 are embodiments of further details of gearing units of the dispensing devices, shown in cross section.

3,115,766 Patented Jan. 7, 1964 FIGURE 5 is a section along line VV of the gearing unit of FIGURE 4 showing pertinent elements thereof.

In the machine illustrated in FIGURES 1 and 2. a plurality of screw dispensing devices, each comprising a dispensing screw 1, a charging nozzle 2 and a hopper 3, are arranged in a circle around a drum 4. This drum 4 is co-ax-iall-y fastened to a reversing :drum 5 forming part of a continuously moving conveyor system, tor example a conveyor belt 511 equipped with driving elements 511. This belt feeds packaging containers P continuously to the machine for filling. The reversing drum 5 is secured to a vertical shafit 56 which is rotated continuously by an electric motor 50 through a belt drive 51, a worm and worm wheel gearing 52, 53 and a toothed gearing 54, 55.

The material to be dispensed in measured amounts is fed to the machine through a pipe 40 whence it passes over a cone 18 and, via the drum 4- and outlet openings 40: of the latter, into the hoppers 3 of the individual dispensing devices.

The driving of the dispensing screws 1 for obtaining accurate discharge of the required quantities of material is eifected through a rotating drum 4 and a toothed ring 7 which is fixed onto the head 6a of the machine frame 6. The drive shaft 13 of each dispensing screw 1 is driven from the toothed ring 7 through a toothed wheel 8, an intermediate shaft 14, a dog clutch comprising clutch elements 27, 32, and further intermeshing toothed pinions 11, 12. The clutch element in FIG. 1 is a driving element and includes a screwthreaded nut seated on a helix or section 30 of a corresponding screw threaded configuration rigidly mounted upon the shaft 14. As a consequence, movement of the clutch element 27 in the axial direction to elfect clutch engagement will produce a simultaneous rotary movement, thereby producing a synchronizing efiect.

In the arrangement illustrated in FIGURES ,1 and 2 the direction of the thread pitch of helix 30 is selected so that the clutch element 27, which will normally turn with the shaifit 14- at the same rate when the clutch is disengaged, is rotatively retarded relative to the shafit as a result of the axial movement, so that at the moment its teeth mesh with those of the stationary clutch element 32, element 27 is almost at a standstill. From this stage onwards the axial movement of the clutch element 27 is so delayed that, during the further inter-engagement of the teeth of the two clutch elements 27 and 32, these clutch elements are brought together to the speed of rotation of the shaft 14.

After a predetermined number of turns by the screw 1, driven in this way, over the period during which the corresponding dispensing device travels through the full reversing section or the conveyor belt 5a, or a selected part of this distance, the two coupling elements 27, 32 are disengaged.

Olutch elements 27, 32 are operated by means of an annular cam rail 15 which is fixed to the machine frame 6 and has running thereover a roller 16 fastened to a lever 17 for each dispensing device. Connected to the lever 17, which is pivotally mounted on a bearing bracket 17b, are arms 17:: which support the displaceable clutch element 27 through a sliding ring 19. The clutch elements are biassed into engagement by a tension spring 20 which pulls the arms 17d downwards to the extent permitted by the cam roller 15.

To enable the amount dispensed, that is to say the number of rotations of the screw, to be varied per operation, a bowed cam piece 15a is mounted at the discharge section alongside the cam rail 15 so as to be displaceable about the rotary aris of the machine. Cam piece 15a is secured to arms 60 which are rigidly connected to a segment 61 which is mounted for displacement about the vertical central axis of the machine. This segment 61 has peripheral teeth engaging two toothed wheels 62, 63. These two wheels 62, 63 are coupled to one another through a chain drive 64, the toothed wheel 62 additionally being connected to a reversible adjusting motor 68 through a shaft 65 and a bevelled pinion drive 66, 67. When the motor 68 is energized, the segment 61 of the cam piece 15a can be shifted about the central axis to vary the moment at which the coupling elements 27, 32 are engaged.

A braking device is provided for each of the screw shafts 13 to ensure arrest of the shaft in the lapse of time between the disengagement and re-engagement of the clutch elements 27, 32. This braking device comprises a brake drum 41 secured to the shaft 13 and a brake shoe 42 which is urged against the corresponding periphery of the drum 41 by a tension spring 43 through a lever 44 and a link 45. The application and release of the braking device is controlled through the agency of an annular rail 46 (which is fixed above the cam rail 15) and a roller 47 which runs on rail 46 and is carried on a lever 44, such that, shortly before the engagement of the clutch elements 37, 42, the brake device 41, 4-2 is released, and the brake is re-operated shortly after clutch disengagement.

Having regard to the fact that the moment at which the clutch elements 27, 32 are disengaged is variable by the cam piece 15a, the moment at which the brake comes into action is adjustable along with the clutch disengagement. For this purpose there is also provided on arms 60 fastened to the segment 61 and arranged above the annular rail 46, a segment 48 at the ends of which the rollers 47 run back on to the lowest portion of the annular rail 46 under the action of the tension spring 43, thus unbraking the screw shaft 13.

To avoid a dispensing operation in the absence of a packaging container P being located beneath the nozzle, a awl 70 is associated with the movable clutch element 27 of each dispensing device through a link '71 and a lever 72 connected to a detector finger 73. When a packaging container P is brought by the conveyor belt beneath the charging nozzle 2 of the dispensing device concerned, the detector finger 73 is pivoted by this container P thereby to release the clutch element 27. If, however, a packaging container P is not detected, the pawl 70 remains in a locking position in which the free end thereof projects into the path of a bearing pin 74 of the clutch element 27 secured to the sliding ring 19, thereby preventing engagement of the clutch.

To ensure that the material charged into the hoppers 3 reaches the screws 1 in loose condition, two continuously-rotating agitating blades 75, 76 are provided in each hopper 3. These are secured to a sleeve 77 which is coaxial with the screw shaft 13 and has a toothed portion which enables the sleeve to be continuously driven from a toothed wheel 78 keyed to the shaft 14, through a transmission pinion 79.

In contrast to the example described above, in which synchronism is effected by reducing the rate of rotation of the driving clutch element 27, in the embodiment illustrated in FIGURE 3 synchronism is obtained by imparting a rotary movement to a stationary driven clutch element 26 corresponding to the rotary movement of a driving clutch part 31. In this instance a helix or screwed section 29 is loosely rotatable on the shaft 14 and, on the one hand, carries the clutch element 26, which is provided with a female thread and, on the other hand, is firmly connected to a toothed wheel '34 which meshes with the toothed wheel 12 of the screw shaft 13. During its axial movement to engage the clutch, the driven clutch element 26 is at the same time subject to a rotary movement corresponding to the rotary movement of the clutch part 31 secured to the drive shaft 14, which causes smooth interengagement of the teeth of the clutch elements 26-, 31 without clashing.

In the embodiment according to FIGUrES 4 and 5 the synchronous movement and the clutch engaging movement take place separately. To this end there is provided, in addition to the cam rail 15 for establishing engaging and disengaging movement of the clutch part 9 which is driven by the drive shaft 14 and is axially displaceable on the latter, an annular cam 24 to impart to the driven clutch part 10 a rotary movement before the clutch engagement.

This driven clutch part It} is connected through a free wheel device 21 with a lever 22 carrying a roller 23 which runs on to the raised part 25 of the annular cam 24 when the dispensing device turns, whereby a rocking movement is imparted to the lever 22. This rocking movement is transmitted to the driven clutch part it) through the free wheel device 21, which becomes locked in this direction of rotation, so that a shock-free and delicately regulated coupling or uncoupling of the clutch 9, 10 is obtained with a very small relative movement between the parts 9 and 10.

We claim:

1. A dispensing machine comprising in combination a rotatable distributor drum, means to feed fiowable loose material upon said drum, means adapted to rotate said drum continuously, a plurality of hoppers mounted beneath said drum and each having a discharge opening, a dispensing screw adapted for filling containers brought into register with the discharge opening of each said hopper, a conveyor for feeding said containers below said openings, means to produce and to control the rotation of said screws in response to the rotary motion of said distributor drum, clutch means for each of the dispensing screws each including a driving element and a driven element for coupling respective screws with said driving means in instantaneous manner, and means for synchronising the rotation of the driving element and the driven element of each clutch means only until the time of engagement of said elements so as to avoid slip between said elements during said engagement, and While permitting, upon engagement, driving of the driven element from the driving element.

2. A dispensing machine as claimed in claim 1, further including brake means for each of said screws, and a fixed cam device acting on said brake means to apply the same in response to the rotation of the part of the drum carrying the dispensing screw concerned past the cam device.

3. A dispensing machine as claimed in claim 1, comprising a drive shaft for each clutch means, the driving element and the driven element of each clutch means being mounted on a corresponding drive shaft for relative axial movement to effect the engagement and disengagement of said clutch elements, and control means to effect the relative axial movement, said control means comprising a rockable lever associated with each clutch means, a fixed cam in the path of the levers of the respective clutch means, a segmental rail alongside said cam, and means for shifting said segmental rail in the direction of travel of said levers and clutch means with the drum.

4. A dispensing machine as claimed in claim 3, in which the segmental rail is connected to a rack, and comprising an electric motor mounted at a stationary position in the machine and coupled to the rack through a toothed gear, thereby to shift the rail and vary the period of coupling of the respective clutch means and hence the quantity of material dispensed by the respective dispensing screw per operation.

5. A dispensing machine as claimed in claim 1, further including a stop device associated with one of said driving and driven clutch elements of each clutch and movable into the path of said element to obstruct axial movement thereof, a detector ringer pivoted on the corresponding hopper and normally disposed in the path of work on said conveyor, and a mechanical linkage between said detector finger and said stop device.

6. A clutch adapted for use in a dispensing machine having a dispensing screw for delivering material therein in proportion to the number of revolutions of said screw, the clutch being positioned between said screw and means for driving the same, the clutch comprising a first element coupled to said screw in driving relation, a second element coupled to said drive means for being rotated thereby, said first and second elements normally being in spaced axial relation and being adapted for connection in driving relation by relative axial movement therebetween, means engaging one of said elements for axially moving the same towards the other of said elements and means for simultaneously rotating said one element upon axial movement thereof so that said elements are rotating at the same relative speeds as they are engaged to avoid slip therebetween, the latter means being operative to release said one element as the same engages said other clutch element whereby the clutch element which is driven by the driving means instantly drives the other of the clutch elements which in turn instantly drives the drive screw whereby the number of rotations of said screw will be equal to the number of rotations of said drive means.

7. A clutch as claimed in claim 6 wherein said means for moving one of the elements is coupled to the second element, the first element normally being at rest, the last said means including a member defining a helix, said second element having a complementary helix and supported on the rfirst said helix so that relative axial movement between said second element and the helix member causes rotation of said second element, said helices being arranged to impart a rotation to said second element which is opposite to the direction of rotation of said helix member caused by the drive means, as said second element is moved axially on the helix member towards the first element so that said second element is stationary as it engages the first element in driving relation.

8. A dispensing machine for charging a measured quantity of material into a container, said machine comprising: material supply means, material dispensing means for receiving material from said supply means, a dispensing screw in said dispensing means for dispensing material therefrom in an amount in substantial accordance with the number of revolutions of said dispensing screw, driving means for rotating said screw, clutch means for substantially instantly connecting said driving means to the dispensing screw, said clutch means including first and second opposed clutch elements facing one another and spaced apart when said screw is at rest, the first of the clutch elements being driven by the driving means, the second of the clutch elements being adapted to be driven by the first element for in turn driving the screw, means for relatively moving said clutch elements towards one another to place the elements into contact whereby said driving means is effective to drive the dispensing screw through the clutch means, and means for rotating one of said clutch elements prior to engagement of said elements to cancel relative rotary movement therebetween such that the clutch elements are engaged free from relative rotary movement therebetween, the latter means releasing said one clutch element upon engagement of the clutch elements at which time said first of the clutch elements then instantly drives the second of the clutch elements and the dispensing screw is brought to the speed of the first element substantially instantaneously.

9. A dispensing machine as claimed in claim 8 in which said driving means includes a driving shaft, the first clutch element being mounted on said driving shaft for axial displacement therealong, the second clutch element being loosely mounted on said driving shaft and being drivingly coupled to said dispensing screw, said machine comprising a free wheel device associated with said first clutch element including an outstanding control lever, and a fixed cam device in the vicinity of said lever to swing the same in a direction to impart a rotary movement through said free-wheel device to said second clutch element.

10. A dispensing machine as claimed in claim 8 where in said means for rotating one of said clutch elements includes a helical element supporting said one clutch element for rotating said one clutch element as the latter is axially displaced on said helical element.

11. A dispensing machine as claimed in claim 10 wherein said one clutch element is driven by the driving means and said driving means includes a drive shaft, said helical element being rigid with said drive shaft for rotating therewith, said helical element having a thread direction which is reversed relative to the direction of rotation of the drive shaft to cause said one clutch element to have reduced rotation as the same axially travels along said helical element towards the other clutch element.

12. A dispensing machine as claimed in claim 10 in which the driving means includes a driving shaft to which the first clutch element is fixedly fastened, the machine comprising a hollow shaft loosely mounted on said driving shaft and drivingly coupled to the dispensing screw, said hollow shaft supporting said helical element thereon, the second clutch element being rotatably mounted on the helical element, said helical element having a pitch which is adapted to rotate said second clutch element in response to axial movement thereof along said helical element towards the first said clutch element.

References Cited in the file of this patent UNITED STATES PATENTS 2,643,026 Craig et a1 June 23, 1953 2,699,072 Wrinkle Jan. 11, 1955 2,942,761 Jungmayr June 28, 1960 

8. A DISPENSING MACHINE FOR CHARGING A MEASURED QUANTITY OF MATERIAL INTO A CONTAINER, SAID MACHINE COMPRISING: MATERIAL SUPPLY MEANS, MATERIAL DISPENSING MEANS FOR RECEIVING MATERIAL FROM SAID SUPPLY MEANS, A DISPENSING SCREW IN SAID DISPENSING MEANS FOR DISPENSING MATERIAL THEREFROM IN AN AMOUNT IN SUBSTANTIAL ACCORDANCE WITH THE NUMBER OF REVOLUTIONS OF SAID DISPENSING SCREW, DRIVING MEANS FOR ROTATING SAID SCREW, CLUTCH MEANS FOR SUBSTANTIALLY INSTANTLY CONNECTING SAID DRIVING MEANS TO THE DISPENSING SCREW, SAID CLUTCH MEANS INCLUDING FIRST AND SECOND OPPOSED CLUTCH ELEMENTS FACING ONE ANOTHER AND SPACED APART WHEN SAID SCREW IS AT REST, THE FIRST OF THE CLUTCH ELEMENTS BEING DRIVEN BY THE DRIVING MEANS, THE SECOND OF THE CLUTCH ELEMENTS BEING ADAPTED TO BE DRIVEN BY THE FIRST ELEMENT OF IN TURN DRIVING THE SCREW, MEANS 